Pheromones
by silentgundam
Summary: "Genos moaned. Softly but deep in the cyborg's throat and so sexual. It may have been a while since Saitama had sex with anyone but there was no denying the nature of what just came out of Genos' mouth. Saitama withdrew his hand. What. The. F-."


Part of Saitama fully expected Genos to combust or something when the monster sent out her latest attack. It froze Genos mid-air, nothing but his hair moving in the wind. But the cyborg just dropped, slamming into the street on his hands and knees with the force to crack the pavement all the way to Saitama's boots. The bee woman drifted lower, coming to hover just above Genos' head.

"Ooh, that's tough, sweetie," she buzzed. Her fingertips grazed the top of Genos' hair and he jerked as though she had electrocuted him. Shit, maybe she had.

"Genos?" Saitama called. "You okay?"

The bee woman's lips twisted as her lashes fluttered Saitama's direction. Then she struck to kill.

The fruit will probably bruise, Saitama thought as he tossed the market bags to rush to Genos' side. He punched the bee woman directly through her chest. She liquified, showering a multimeter circle around them in maroon blood. Saitama turned to look just at his hip, where Genos remained on his hands and knees and unnaturally still.

"Genos?"

No answer.

Saitama squatted down, placing a hand on Genos' metal shoulder.

Genos _moaned_. Softly but deep in the cyborg's throat and so _sexual_. It may have been a while since Saitama had sex with anyone but there was no denying the nature of what just came out of Genos' mouth. Saitama withdrew his hand.

What. The. Fuck.

"Uh…feeling alright, man?"

Genos didn't move, didn't say anything. His whole body was rigid. After hearing that moan, though, Saitama could guess what was happening.

"That bee bitch made you all horny, huh?"

"It's not like that, Teacher," Genos gritted. At least now he just sounded angry.

"You're right, she was too freaky to get even a cyborg's rocks off. Probably that last pheromone she sent out, huh?"

"Pr...precisely."

"Well, no sweat. You have a fan club, right? We'll find you a pretty girl in no time."

"Teacher...I...I don't even have genitals," Genos spat at the ground. "The most organic part of my body is my face, and even that is...artificial. Sex can't...solve the problem."

"Oh."

And that about summed it up. Genos always needed answers, solutions. Not having one now was probably pissing him off more than anything the monster did to him. Not knowing what else to do, Saitama patted his friend's shoulder. The ultimate sign of comfort.

Genos moaned again.

Right.

"Guess you just gotta wait it out, then. Think about something else."

"I'm trying, but it's not working. I think Queen Bee's pheromone is...not letting me."

"Oh."

That would make sense. All the other subjects of the bee bitch's pheromones only seemed to be free of the effects once they accomplished their tasks. But if Genos didn't even have a dick to have sex...how else do you solve a horny problem? Maybe it was affecting Genos differently than it was supposed to, him being a cyborg and all. But he had said his face was the most organic part of him. Maybe he just needed his face to be touched? Genos was his friend, his student, all that crap. Saitama could help him out. He didn't have to fuck a robot, he was just going to touch the guy's face. With a quick breath, Saitama reached and cupped the far side of Genos' face, gently pulling for the cyborg to look at him.

Surprisingly, there wasn't another moan. Maybe Genos' confusion, which dilated those electronic pupils wide, overwhelmed the sensations. Saitama smiled weakly at Genos.

"How's that?"

Abruptly, Genos' eyes sharpened. Saitama blinked once then found Genos lurching forward. A metal arm wrapped around Saitama's waist and a cool hand gripped the base of his skull. Their chests pressed together an instant before Genos slammed his lips on Saitama's.

The moan that Genos let loose into Saitama's open mouth was obscene. Saitama's eyes blew open wide. It wasn't that Genos' intensity or eagerness was necessarily surprising; forced horniness aside, Genos had never been shy about his admiration of Saitama. This was the first time Saitama wondered if maybe it wasn't all totally student-teacher, though. What _was_ surprising was the spark deep in Saitama's chest when Genos began moving his lips firmly against his own. The spark ignited a fluttering that raced through Saitama's veins as he felt Genos nibble his bottom lip. Saitama's eyes finally closed and he relaxed into the embrace, bringing both hands up to Genos' face as he slipped his tongue into Genos' mouth.

Genos moved again, hands and lips never leaving Saitama as he brought them to their feet and pushed Saitama against the adjacent shopfront. For all the force Genos was using in his grip, it was with unexpected gentleness that Saitama's back touched the brick. Genos' tongue met Saitama's then, and it felt just as human as the skin on his face did.

It was becoming contagious, the bee woman's pheromone. It had to be, Saitama thought as he returned Genos' kiss with just as much excitement, blood surging south and making his very-human dick think he could _totally_ fuck a robot, or at least be ready for whatever this could possibly turn into.

It couldn't turn into anything, Saitama firmly tried to tell himself, tasting Genos and letting his hands run up and through that blond mop of hair. Genos was six years younger than he was, Genos was his student, Genos was a guy, Genos was a cyborg, Genos had been through so much unresolved trauma he was a walking warning of the dangers of revenge.

But the reasons to stop we're getting lost in the fire that was taking over Saitama. It wasn't the same fire as fighting someone who could take more than one punch, but the fire was still hot and making Saitama feel more alive than he had even in his fight with that weird alien with one eye. Genos' lips were growing frantic, and when he missed Saitama's lips and landed just north of his jawline, Saitama felt his mind start to blank. Very human-feeling lips began sliding toward his neck, sucking just enough to notice, sending lightning throughout Saitama's body.

Fuck.

Rock hard and not entirely sure why he had debated stopping at all, Saitama moved his hands to Genos' shirt. He rubbed the cyborg's chest once, hands moving outward to wrap around the machinery that made his imitation of biceps. Genos kissed his way up Saitama's neck and flicked his tongue out, sending shockwaves at the earlobe the moment before he brought it between his teeth. Putting the last few operable brain cells he had into not fucking obliterating Genos' arms, Saitama let his head fall back as he let out a moan of his own. There was absolutely no reason a virgin cyborg should be this good at kissing.

Genos tensed minutely. His throat seemed to catch as his own moan turned into a whimper that told Saitama something worth knowing. Genos was getting off on Saitama's sounds. Just to test it, Saitama moaned again, barely louder than before. The result was the same; a hitched whine, a tensed spine. Awesome.

Eyes still closed and face toward the sky, Saitama let Genos render him to goo with his lips. Not quite forcing it but definitely making more noise than he typically would, Saitama made sure to tilt his face just enough to let his breath hit Genos' ear every time he moaned. The shivers and whimpers coming out of the cyborg were growing more frequent, more urgent, and Saitama was pretty sure he was unraveling, too. His hips bucked instinctively when Genos let out a near-growl after several moments.

Lips crashed into Saitama's, full force and desperate. He couldn't help the guttural hum that came out, and Saitama had to will himself not to cum in his pants like a teenager when Genos moaned his name directly into his mouth. The cyborg's body stiffened and stuttered, then stilled.

They were still pressed together, head to toe, against the shopfront in the middle of the street bathed in monster blood, but nothing seemed to exist outside of Genos' lips resting against Saitama's. The intensity was gone, leaving an exhausted Genos panting heavily with his eyes screwed shut. Gently, Saitama pressed a few soft kisses to Genos' frozen lips before pulling his head back just enough for their eyes to meet.

Genos looked...exactly as he always did. Face pale and composed, shirt not even rumpled, not a strand of hair out of place. There was no way Saitama didn't look the horny wreck he felt, but Genos had the cyborg facade to keep him looking perfectly fine. However, Genos' eyes were rapidly analyzing, adjusting, calculating.

"So," Saitama said, clearing his throat. "Feeling better?"

Genos vanished from Saitama's arms, shooting back several feet. He stood in the center of the empty street, still panting, and blinked several times.

"Teacher...I...I am so sorry."

Sorry? Of course Genos would passionately make out with someone who obviously enjoyed it and was now rock hard in _spandex _and then apologize. "Dude, don't. It was-"

"No, no, I am..." Genos looked at the ground. "I am ashamed and I am sorry." And then he was gone.

"Ugh." Saitama rubbed his face a few times, trying to will his dick to behave long enough for him to walk home. He wasn't terribly surprised by Genos' reaction. The guy was probably mortified. Saitama shrugged as he collected their market bags. He'd just talk to him at home later, explain that he enjoyed himself, too.

Genos wasn't at home when Saitama made it back to the apartment. Again, not surprising. But when Saitama had made, eaten, and cleaned up dinner, read through two volumes of manga, and was staring at the dark ceiling of his night-drenched home, he officially began to wonder where Genos could have gotten to. Where did he live before he barged into Saitama's place? He hadn't ever thought to ask. Maybe Genos was crashing on the operating table at his doctor's place. _That _was a little depressing.

"The monster is threatening the shopping district of City X," the news reporter said on Saitama's television the following morning. He lowered his manga. "There are reports that the Class S Hero, Demon Cyborg, is on the scene and handling the situation, but officials are still ordering everyone to clear the area until further notice."

"Ah, there he is," Saitama muttered, collecting his hero uniform. "Little shit."

The news hadn't shown a picture or video clip of the monster, but City X had a pretty popular shopping district that was easy to spot from the highest building in City Z, not far from Saitama's apartment. He couldn't see exactly what was going on, but in the few moments he stood on the roof ledge, Saitama saw the hot flashes of Genos' fiery blasts. He leapt, and he ran.

When Saitama turned the final corner a few minutes later, something huge and on fire was barreling through the open air directly at him. Just before he stepped aside to avoid it, however, Saitama recognized Genos' body in flight and instead opened his arms wide enough to intercept him. Genos' back crashed into Saitama's chest, sliding the red boots back a few feet in the pavement. Mechanical muscles and weapons hot as the sun beneath his gloved fingers, Saitama couldn't quite resist making sure to wrap his hands around Genos' waist, just at the belt line. Genos turned his head up and caught Saitama's eye.

"T-Teacher?"

"Hey, Genos." Saitama smiled. Genos looked away, but he didn't try to move. Saitama took it as a win. "I was worried when you didn't come home last night."

Genos looked back up, frowning. "Worried?"

"Well...yeah. You're always back in time to brush your teeth."

"I...I wasn't sure you would appreciate my company."

"Really?"

"Of course, Teacher!" Genos said, looking pained. "After...after I just-"

An ear-splitting roar interrupted Genos. Down the street from them, an enormous...Saitama squinted. Was that a twenty-foot teddy bear? For all the fluff and pink bow around the ear, it did seem rather destructive. Genos shot Saitama a strained look, then pushed off him to leap back into battle. Saitama crossed his arms as he watched Genos attack the bear with flames that somehow didn't scorch the fur.

So _that_ was why Genos was so embarrassed. He thought he had forced himself all over Saitama. Well, technically speaking, Genos had. But surely the cyborg wasn't so dense that he hadn't noticed how enthusiastically Saitama had responded. Surely.

Genos' arm flew toward Saitama's face as the bear finally burned to the ground in a burst of heat. Saitama snatched the metal limb from the air and made his way over to Genos.

"You really should stop letting your guard down around monsters, dude," Saitama said as he offered it back to Genos.

Genos took his arm and nodded without looking away from the charring fur. Damn, this was probably going to require Saitama to do all the work. He reached over and caught Genos' chin between his thumb and crooked forefinger, forcing Genos to look at him.

Who knew electronic eyes could convey confusion so well?

"But," Saitama said, hoping his smile was encouraging, "you're welcome to let your guard down around me."

Genos' mouth fell open a little bit, and Saitama felt he had covered enough ground talking. He leaned up and pressed his lips to Genos'. Much as he would have enjoyed the intensity of the previous day, Saitama kept the kiss short and sweet. There'd be time for passion later.

"Teacher," Genos said softly as Saitama pulled away. "I don't understand-"

"Okay, 1) stop calling me that. It's just Saitama from here on out."

"Oh, uh...I will, Saitama."

"Great. 2) I obviously like kissing you, so try not to have an existential crisis every time I do it."

Genos' eyes grew wide. "Every...?"

"Yep."

"But, but T- but Saitama, I don't think you realize what-what happened yesterday."

"Fair enough. Care to explain?"

Genos took a tiny step back, forcing Saitama to drop his hand. The cyborg screwed his eyes shut and took a deep breath before opening them again.

"Saitama, I am all machine but for my brain. I...for a long time, I was convinced that...that sexual desire was not possible."

"Is this a long story, Genos?"

"I will keep to the points of import."

"Cool."

"But...at some point...I discovered that emotional attraction caused my body to react very similarly to physical arousal. After some experimenting, it became obvious that touches to my face could solve the problem, in addition to...to..." Genos pursed his lips, clenched his single functioning fist.

Saitama frowned. "In addition to what? Touching your face wasn't enough? It seemed to do the job yesterday."

"The touch has to be delivered by or mentally associated with the source of my emotional attraction to satisfy the physical arousal."

Saitama blinked. "Uh..." What? That was just technical mumbo jumbo. He'd really have to teach Genos how to talk in plain terms...wait. "Wait, so you...in order to get off, you have to...to imagine the person you like? Or they have to be the one that's touching you? Ohhh, then-"

"Yes, Saitama. I have...had an emotional attraction to you for...quite some time." Genos cringed inward on himself slightly. "I am sorry for not having told you earlier. I did not believe it appropriate, given that you had taken me on as your student and allowed me to live with you. I tried to make the attraction fade on its own but to no avail. Even if we were to pursue anything together, I don't-I don't even have genitals to provide the sexual relationship that is so vital to long term success, and-"

"Holy shit, Genos, shut up," Saitama laughed. "We're not married, dude. I like and respect you and just discovered I like kissing you. Nothing past that is changing right now. There's more to relationships than just sex, you know. I've been fine without it for a long time now. Besides," he said, waggling his brows at Genos. "You have a mouth and hands, right?"

Genos' face didn't change for a moment, but Saitama could see the exact moment that his words found meaning in the cyborg's human brain. Genos' eyes grew huge, jaw dropped, and if he could have, there was no doubt his face would have turned a brilliant shade of red. Saitama burst out laughing, stepping forward to clap his hand on Genos' shoulder.

"Just stop thinking. Enjoy things as they happen, you know?"

"I...I will try, Teach-Saitama." Tentatively, Genos returned Saitama's smile, making him look more human than any upgrades could. "Could I kiss you now?"

"Dude, you can kiss me anytime you want."

Genos' lips fit perfectly against Saitama's, sparking that hidden fire he had long thought could only be stirred by battle. He ran a hand through Genos' hair, pleased that the cyborg seemed to have lost some of his uncertainty as he cupped Saitama's face. And, fire burning under his skin properly now, Saitama took his own advice and stopped thinking, just enjoyed.


End file.
